Screen capture Web Page, selected region or whole browser window, edit screenshots and save the images to Local File or Google Drive. Edit screenshots in a very user-friendly interface with the different tools.

Firefox OS Simulator is a test environment for Firefox OS. Use it to test your apps in a Firefox OS-like environment that looks and feels like a mobile phone. After installing it, go to Web Developer > Firefox OS Simulator to access its features.

Access important SEO metrics while you surf the web. This toolbar from Moz lets you see metrics like Domain Authority and Page Authority for every page you visit, analyze links as you browse, expose page elements, and access other SEO tools.

The easiest way ever to change IP and browse anonymously! Just activate it with one click and it's done, you're browsing the web with a random HTTP or Socks proxy list from several countries in the world. No ads. 100% free to prevent web censorship.

Create a QR Code of the selected text or current URL. Customize image with different colors and sizes.Use CTRL-SHIFT-Q to quickly see the QR Code. Also possible to create a QR Code from free text within Firefox. Works completely offline!

The easiest way to control Xdebug:+ set tracing, profiling and remote debugging in one click!+ configure your IDE key in addon preferences!+ based on Jetpack, so it's restartless+ animated iconsInstallation: http://manual.pohape.ru/xdebug/

Free Visio Viewer by Lucidchart enables Firefox users to open Microsoft Visio files attached to their email (Gmail / Google Apps) or posted on a website. No sign-up required to open a read-only version.